Sensors are used in innumerable systems, such as systems in automobiles, other machines, aerospace, medicine, manufacturing and robotics. Sensors measure physical parameters and convert them into signals that can be read by an observer or electronics.
Automobiles include sensors in systems that are critical for the safe operation of the vehicle. These critical systems include control systems and safety systems, such as electronic power steering (EPS) and vehicle stability control (VSC) systems. Often, these critical systems employ redundant sensors for gathering data on the same parameter. For example, a steering sensor system may include redundant steering angle sensors and/or redundant steering incremental speed sensors that provide data to the EPS and/or VSC systems.
Typically, a sensor is connected to one or more circuits, such as supply circuits and a control circuit, via wires that extend from the sensor to the circuits. The sensor can be connected to the circuits via a controller area network (CAN) bus or point-to-point connections. Usually, a CAN bus includes six wires for providing power to a sensor and communicating with the sensor. In addition, each CAN bus includes a CAN receiver that adds cost to the final product. Point-to-point connections include two and three wire per sensor connections, where data can be communicated via current modulation in a two wire per sensor system and data can be communicated via voltage in a three wire per sensor system. In all of these systems, wires, including wires for redundant sensors, add cost and weight to the final product.
For these and other reasons, there is a need for the present invention.